Street Design

As new transportation modes emerge and demands for street space increase, how can the needs of all modes be met?

Bicyclist riding on protected red bike lanes in the center of busy street in Sao Paulo, Brazil

Photo by Vinicius Bacarin on Shutterstock

COVID-19 IMPACTS

Closing streets to automobiles and adding on-street dining areas are two examples of how street design changed during the Covid-19 pandemic to accommodate physical distancing. Urbanism Next explored more changes to urban design, including these temporary changes to street design, on the Urban Design Covid-19 Impacts page.

Read Urbanism Next's two new reports in the Covid-19-- Impacts to Cities and Suburbs series, Key Takeaways Across Multiple Sectors and Impacts to the Urbanism Next Framework, to learn how the Covid-19 pandemic is changing different elements of urban living, including to transportation, urban design, building design, and e-commerce.

What is driving change?

Change in Parking Demand

The demand for parking is predicted to drop as much as 90% as transportation network companies (TNCs) and autonomous vehicles (AVs) reduce the need to store cars at destinations. Parking has become a primary determinant of urban development, so a change in parking demand will have dramatic effects on urban design.

Change in Congestion

Transportation network companies (TNCs) are already contributing to increased congestion in urban areas and autonomous vehicles (AVs) are predicted to exacerbate the problem. The increase in congestion could put pressure on street design to facilitate increased travel speeds. In mitigating for this congestion, streets will continue to be a battleground of competing strategies, especially as on-street parking needs are potentially reduced, freeing up usable space in the right-of-way.

Shift in Modes

An increase in on-demand rides coupled with a reduction in transit, walking, and cycling trips could have substantial impacts on urban design as it might increase the demand for additional vehicle travel space. Additionally, a reduction in transit use could reduce the vibrancy and viability of transit-oriented development. Shifting from transit, walking, and biking to autonomous vehicles (AVs)—ostensibly a mobile, enclosed, private space—could also reduce the vitality these more active modes add to street life.

Competition for the Right-of-Way

Increased competition for the right-of-way (ROW) impacts street design and, in particular, the amount of space that is allocated to each mode. It could also impact the priority given to each mode along the street and could exacerbate current areas of mode conflict. These types of concerns are already leading to calls for redefining mode prioritization for streets and increasing the efficiency of ROW use, particularly in regards to curbside access.

Shifting Nature of Freight

One of the criteria that keeps urban design relatively compact is the burden of travel time to get to goods and services. Both suppliers and consumers prefer shorter travel times to acquire goods and services. A combination of autonomous vehicles (AVs) and e-commerce could reduce the importance of this preference for consumers as the delivery of goods masks consumer’s perception of the burden of travel.

Future Changes

People walking and sitting on city street in Tokyo

Photo by Daniils Petrovs on Unsplash

What Could Happen?

The allocation of street space could shift. Most streets are designed for cars with few, if any, accommodations made for micromobility within the ROW. Demand for car-oriented lane space could be reduced by widespread autonomous vehicle (AV) usage if AVs require less lane width for safe operation. Additionally, reduced parking demand could free up on-street parking space, making it available for other uses. A major question here will be the stated priorities for how space should be allocated on streets. If multimodal access is a primary concern, any available ROW could be designated for pedestrian, micromobility, and transit use. Conversely, if congestion is a primary concern, any available ROW could be allocated for more vehicle lanes.
There could be an increase in curb-side congestion. As transit, TNCs, AVs, need access to curbs for pick-ups and drop-offs, bikes and scooters need access to sidewalk parking and charging areas, and delivery vehicles need access to stage and deliver parcels, the fight for curb space could increase. Increased congestion at the curb could also overflow and create congestion in travel lanes.
There could be an increase in bike and scooter infrastructure. As more non-personal vehicle transportation options grow in popularity, there will be increased demand for dedicated ROW for these modes. Providing safer and improved infrastructure for non-car modes, including transit, would help increase travel efficiency, promote public health, and could support greenhouse gas emissions reductions goals.
Modes could be separated from one another. If AVs are easily disrupted by pedestrians or cyclists, there may be pressure to physically separate modes to avoid conflicts, prioritize AV efficiency, and avoid dangerous situations.
Continuous street fronts could become more commonplace. With the reduced need for parking, buildings could move closer to the street or new buildings could be built within existing parking lots, helping create a continuous street front that is more inviting to pedestrians.

Light rail in the middle of busy street in Amsterdam with pedestrians on either side

Photo by redcharlie on Unsplash

EVIDENCE TO DATE

TNCs and goods delivery are causing curb congestion. TNC passenger pick up and drop off is creating increased congestion at the curb, as well as in active travel lanes as passengers pick up or end rides in traffic due to a lack of curb access for this new and popular travel mode. At the same time, e-commerce has resulted in increased package deliveries. In 2018, there were 15 billion e-commerce packages delivered in the US. This increase in package delivery is having a distinct impact on curbside congestion.
TNCs are causing increased congestion on city streets. TNCs are causing a disproportionate amount of congestion on streets as they have added new trips and increased vehicle miles traveled due to travel to and from passenger pick-ups and drop-offs. Almost half of all TNC vehicle miles traveled are with only drivers (not passengers) in the car.
Micromobility use is increasing heavily. In 2018 there were 84 million micromobility trips in the US, up from 35 million the year before. The majority of these trips, 38 million, were scootershare trips. This is a significant increase in demand for street space allocated to micromobility and it is projected to continue to grow.

Quick facts

Si aliae qui ommolenet que prati aut eossitae optatus daepell uptatur andante comni idebit quid moluptio te am quat facculparum recaecte.

Micromobility trips more than doubled from 2017 to 2018, demonstrating a growing need for micromobility considerations in street design.
In the United States alone, 15 billion e-commerce packages were delivered in 2018, creating extensive curbside congestion and requiring new approaches to street design.